The invention relates to novel microparticles, the preparation thereof and the applications thereof in biology, especially in the culture of animal, and in particular human, diploid cells, normal or infected for example by a virus or a parasite.
It is known that normal diploid cells which are cells of embryonic origin are used for elaborating different products of cellular origin, such as interferons, or else for culture of viruses suitable for the manufacture of viral vaccines for human use.
But the production of these cellular elements on an industrial scale is difficult due to the requirements for the culture of normal diploid cells. In fact, contrary to transformed cells, which are capable of developing in suspension in a liquid medium, so with a satisfactory yield, normal diploid cells can only multiply on a solid support.
Single layer culture on a solid support of a large quantity of cells in Roux boxes or in rollers requires a large number of containers, which constitutes a limiting factor and has proved unusable for commercial purpose. Research has been carried out with respect to solid carriers for carrying out cultures adaptable to mass culture conditions in fermentation tanks.
Microparticles or beads, in general in the form of microbeads of a diameter of about 40 to 200 .mu.m have more particularly attracted attention for this purpose. They allow in fact substantially homogeneous cultures to be carried out adaptable in principle to culture conditions in a fermenter. They have furthermore the advantage of offering a large culture surface, which allows an increase in the produced cell yield.
However, microbeads known up to present do not entirely satisfactorily resolve the particular problems of adherence, multiplication, toxicity, met with in the culture of normal or infected human diploid cells.
Now, the work carried out in this field by inventors has established that particular microcarriers, especically for the culture of diploid cells allowing an extremely satisfactory adherence and growth of cells on their surfaces, could be elaborated from some types of proteins used for the formation at least of their surfaces.
The invention relates then to novel microparticles favoring, because of their composition and the properties which result therefrom, the adherence and the growth of human diploid cells.
It also relates to a process for preparing these microparticles.
In accordance with another aspect, the invention relates to the application of these microparticles to the culture of cells, more particularly normal human diploid cells, and to the culture of infected diploid human cells or with the in situ infection thereof in view.